// 987654321  *  123456789  =  ?
#include <stdio.h>


int main()
{
    int a[] = {1,2,3,4,5,6,7,8,9};
    int b[] = {9,8,7,6,5,4,3,2,1};
    int c[19] = {0};
    int l;
    for(int i = 0; i < 9; i++)
    {
        for(int j = 0; j < 9; j++)
        {
            c[j+i] += a[j] * b[i];
        }
        for(int k = 0; k < 18; k++)
        {
            if(c[k] >= 10)
            {
                l = c[k] / 10;
                c[k] %= 10;
                c[k+1] += l;
            }
        }
    }
    int flag = 0;
    for(int i = 18; i >= 0; i--)
    {
        if (c[i] != 0)
        {
            flag = 1;
        }
        if(flag == 1)
        printf("%d",c[i]);
    }
    printf("\n");
    return 0;
}